1. Field of the Invention
This invention relates to an intrabox temperature display device for displaying a temperature approximate to a real temperature for cooling and/or freezing foods housed for preservation in a cooling compartment and/or a freezing compartment.
For preserving frozen foods now prevailingly marketed for a long term in a cooling chamber or a freezing chamber, it is desirable to display the cooling or the freezing temperature of the foods preserved in the chamber in a simple and easy manner.
2. Description of the Prior Art
In one of the conventional intrabox temperature display devices, an intrabox temperature detected by a temperature sensor attached to the inner wall of the intrabox, for example, is detected in the form of a voltage divided by the temperature sensor and a reference resistor connected in series with the sensor. The divided voltage is applied to an A/D converter where it is converted into a digital signal. The digital signal converted is then applied through a decoder to a display drive circuit. The signal outputted from the display drive circuit is used to drive a display device such as a three-digit LED display device for digitally displaying the signal representing the intrabox temperature detected.
The intrabox temperature displayed by the conventional display device as mentioned above is the temperature in the space of the cooling or freezing chamber and not the temperature of the foods per se, since the temperature sensor is merely attached on the wall of the chamber. Attempts have been made in which the temperature sensor is directly made to contact with the individual foods but has been unsuccessful in practical use. Further, an air temperature within the chamber irregularly changes when the door hingedly mounted is open and close and when the compressor is turned on and off. Therefore, the air temperature detected by the temperature sensor does not represent the correct or near temperature of the foods stored.